Study of pro- and anti-oxidative properties of D-penicillamine in a system comprising high-molar-mass hyaluronan, ascorbate, and cupric ions.

OBJECTIVES

The study presents results of pro- and anti-oxidative effects of D-penicillamine on hyaluronan degradation by ascorbate plus cupric ions.

METHODS

The well established degradative system comprising high-molar-mass hyaluronan and ascorbate plus Cu(II) ions was used. Primarily, the effects of replacement of ascorbic acid in this system by D-penicillamine were investigated. Then, D-penicillamine was added into the above degradative system before reaction onset or 1h after the reaction had started. To monitor hyaluronan degradation kinetics, rotational viscometry was applied.

RESULTS

No hyaluronan degradation occurred when ascorbate was replaced by D-penicillamine. The drug addition into the complete degradative system at the reaction onset caused a marked inhibition of hyaluronan degradation. However, the inhibitory effect turned to a pro-oxidative one within appr. 1 h.

CONCLUSION

The dual behavior of D-penicillamine on hyaluronan degradation can relate to: (i) the drug completely traps *OH radicals generated from ascorbate plus Cu(II) ions under aerobic conditions; (ii) thiyl radicals generated from D-penicillamine react with D-penicillamine anions resulting in novel radical reactive species, which e.g. by reducing dioxygen molecules can generate further *OH radicals.